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BY Panda ..7 vl- 7204441011 Feb 14, 1956 A. s. CHANDLER 2,734,324

COVER CLOSING MACHINE Filed April 17, 1952 5 Sheets-Sheet 3 AUSTIN S. CHANDLER INVENTOR.

BY 720mm e., www

United States Patent O COVER CLOSING MACHINE Austin S. Chandler, Fitchburg', Mass., assignor to International Paper Box Machine Company, Nashua, N. H., a corporation of New Hampshire Application April 17, 1952, Serial No. 282,885

13 Claims. (Cl. 53'147) This invention relates to a machine and method for automatically closing the cover of paperboard boxes after the contents have been inserted.

One object of the invention is to provide a machine which can be used in conjunction with various types of box forming machines to form a complete packaging unit.

Another object of the invention is to provide a cover closing machine capable of also infolding and inserting the usual front dust flap on the cover as well as the side dust flaps whether the side dust flaps are on the cover or on the box.

A further object of the invention is to provide a method of closing the cover and infolding' the dust flaps of a filled box which includes preventing the bendable cover from bowing or twisting during the infolding of its dust flaps.

Still another object of the invention is' to provide a machine in which all of the folding'operations take place While the box is slidably advancing against an elongated vertical rear wall and all of the folding means are adjustable in position with relation to that rear wall to accommodate boxes of various sizes.

A still further object of the invention is to provide novel means for transferring the box from merely riding on a packing belt or feed belt to a position in which it is firmly held in a predetermined location on an advancing conveyor which carries it through folding zones.

Another object of the invention is to provide novel means for infolding the front dust flap of the cover' and novel means for infolding the side dust flaps' while closing the cover.

In the drawings,

Fig. 1 is a plan view of the machine showing diagrammatically a typical box forming machine, material conveyor and packing apron.

Fig. 2 is a front elevation of the machine.

Fig. 3 is a rear elevation of the machine.

Fig. 4 is a transverse sectional view, with parts broken way from the discharge end of the machine.

Fig. 5 is an enlarged transverse sectional view on line 5 5 of Fig. 2 showing the box transfer means of the device.

Fig. 6 is an enlarged transverse sectional view on line 6-6 of Fig. 2 showing the first folding means of the device.

Fig. 7 is an enlarged transverse sectional view on line 7-7 of Fig. 2 showing the second folding means of the device.

Fig. 8 is an enlarged plan view of the cover closing head and the side dust ap infolding arms of the device, and their operating mechanism.

Fig. 9 is an enlarged transverse sectional view of the cover closing head on line 9--9 of Fig. 8.

Fig. l() is an enlarged transverse sectional viewv of one of the side dust flap infolding` arms of the device on line 1010 of Fig. 8.

f- 2,734,324 1C@ Patented Feb. 14,- 1956 Fig. 11 is a perspective view of one type of box which may be closedl in the machine. y

Referring to Fig. 11 the box F is made of bendable paper board suitably cut, creased or scored to be set up from a flat blank in a box forming machine G. Box F includes a bottom panel 600, a front panel 601, Va rear panel 602, opposite side or end panels 603 and 604, an articulated cover 605 and a front dust flap 606 articulated to the cover. Also included on box F are apair of side, or end, dust aps 607 and Y608 which as shown in full lines are usually articulated to the cover but as shown in dotted lines at 609, 610 may be articulated to the side panels 603 and 604.

Box F may be set up in any well known manner by meansl of glued tabs, interlocking tabs, stays or theV equivalent, and a plurality of such boxes may be delivered from the machine G onto a packing apron, such as 700. As indicated in Fig. 1, a material conveyor 702 may be located beneath packingapron 700 bothbeing within easy reach of operatives 703, 704 who till each box as it passes on the packing apron.

The cover closing machine of this invention designated generally A, may be set up in extension of a packing apron suchY as 700 upon which the boxes are traveling with one end foremost. The machine A may also be set up at right angles to a packing apron 700 upon which the boxes are traveling front or back foremost,l thus causing the boxes to travel end foremost and occupying less room in the packing plant.,

As shown in Figs. 1 and 2, the cover closing machine A includes a box receiving conveyor belt for receiving the boxes such as F from a packing apron and includes continuously moving box conveyor means B which overlaps box receiving conveyor belt 100 at a box transfer zone 300 and conveys eachv box individually, successively and continuously through a first folding zone 400 and' a second folding zone 500'. The machine A also includes box transfer means C at the b`o`x transfer lzone 300, rst stationary folding means D at the rst folding zone 400 and second folding means E including second stationary folding means and moving folding means at the second folding zone 500.

The machine A has a frame 101, supported/on four legsV such as 102 and is provided with a motor 103 mount!- ed on a motor support 104; A drivingy pulley 10S is powered by motor 103 and rotates a driven pulley 106, through a belt 107, pulley 106 being mounted on a shaft 109 suitably journalled on frame 101. A driving pulley 111 is fixed to shaft 109 and powers a driven pulleyV 112 through a belt 113, pulley 112 being mounted onaA shaft 114 also suitably journalled on frame 101. The various moving parts of the machine A all derive power from shaft 114 and are as follows.

A cylindrical cam track 115 is mounted to rotate with shaft 114, the curved surface 116 thereof beingv in contact with a cam roller 117 carried at the lower end of a lever 118 pivoted centrally to frame 101 at 119. The upper end of lever 118 is in contact with the boxtransfer means C at the box transfer zone 300 andv actuates the saine.

A sprocket 120 is mounted to rotate with shaft 114'and is connected by a chain 121 to a sprocket 122 on the end of the shaft 123 suitably journalled in frame 101. Shaft 123 carries a pulley 124 for one end of conveyor belt 100, the opposite end of the box receiving conveyor belt 100 being trained around an idler pulley 125 carried on a shaft 126. A tension sprocket 127 mounted on an arm 128, pivoted at 129 to frame 101 may be used to maintain the tension of the chain 121.

Another sprocket 130 is-mounted `to revolve with shaft 114 and is connected by a chain y131 to a sprocket 132 on the end of a shaft 133 suitably journalled in frame 101. Shaft 133 carries a sprocket 134 for one end of a chain 200 forming the continuously moving box conveyor means B, the opposite end of the chain 200 being trained around an idler sprocket 135 carried on a shaft 136. A tension sprocket 137 mounted on an arm 138 pivoted at 139 to frame 101 may be used to maintain the tension of the chain 131.

As best shown in Fig. 3, still another sprocket 140 is mounted to revolve with shaft 114 and is connected by a chain 141 to a sprocket 142 on the end of a shaft 143 suitably journalled in the vertically movable supporting assembly 510 for the second folding means of the niachine. Shaft 143 carries a sprocket 144 for one end of a chain 501, the opposite end of the chain 501 being trained around an idler sprocket 145 carried on a shaft 146.

The vertically movable supporting assembly 510, also best shown in Fig. 3 includes a vertical plate 150, having integral threaded sleeves 151, 152 at one side and integral threaded sleeves 153, 154 at the other side. A pair of parallel vertical posts 155 and 156 are revolubly mounted in Unthreaded sleeves such as 157, 158 on the rear of frame 101 and each post is provided with threads at 174, 175 to engage in threaded sleeves 151, 152 or 153, 154. At the lower end of each revoluble post 155, 156 is a sprocket 159, 160, the sprockets being connected by a chain 170. Suitable means are provided at the top of a post such as 156 for example a nut or hand wheel or a rectangular socket 1'71 to enable the post to be revolved in its sleeve 157 or 158. The supporting assembly 510, can thus be raised or lowered to accommodate boxes of various sizes by revolving a single post such as 156, which by means of chain 170, revolves the other post and causes the threaded sleeves 151, 152, 153 and 154 to move along the threads of the posts 155 and 156.

Box conveyor means The box conveyor means B of the machine A includes the chain 200 above mentioned continuously moving along an elongated, vertical rear wall 201 substantially co-extensive with the chain. Rear wall 201 and chain 200 are positioned beside the horizontal box receiving conveyor belt 100 to overlap the same and thereby form a box transfer zone 300. Rear wall 201 acts as a stationary guide rail against which each box such as F is moved and held during its progress through the inachine and chain 200 is provided with spaced upstanding lugs,.such as 202, each arranged to advance a box F along the wall 201.

Preferably a longitudinally slotted bottom wall is provided comprising a pair of elongated, horizontal bottom guides 203, 204 having an elongated slot 205 thereben tween in which the upper stretch 206 of chain 200 travels. Each lug 202 on the upper stretch 207 of chain 200 projects above the slot 205 and guides 203, 204 to advance a box F therealong. A front wall 210 is also provided extending from the end of the box transfer zone 300 through the folding zones 400 and 500 to the discharge end of the machine. Front wall 210 is laterally adjustable to vary the width of the box channel or trough formed by rear wall 201, bottom guides 203, 204 and front wall 210 and thereby accommodate boxes of different widths. Lateral adjustability is secured by brackets 212 and 213 fixed to front wall 210, each bracket being held in place in one of a pair of parallel tracks 214 or 215, extending transversely of the machine, by bolts 216 or 217. A portion of the rear wall 201, at 220 is vertically slidable with relation to the remainder of the wall in the folding Zones 400 and 500 and is attached to the supporting assembly 510. Thus the rear wall does not create an obstruction for the parts of the moving folding means of second folding means E carried by assembly 510 when a box is unusually shallow.

A stationary element 230, which I call an interceptor element, is preferably mounted to extend over the conveyor belt and into one side of the path of the boxes F riding thereon. A movable member 231 is also provided adjacent element 230, the member 231 being mounted on a lever 232 which in turn is actuated by a cam track 233 mounted on shaft 136. Since sprocket 135 of chain 200 is carried by shaft 136, the movable member 231 is synchronized to advance laterally of the belt 100 to push a box such as F past interceptor element 230 and into the box transfer zone 300, when the chain 200 is ready to receive another box.

Box transfer means The box transfer means C of the device is located in the box transfer zone 300 and includes a box pusher member 301 positioned on the opposite side of continuously moving, box receiving conveyor belt 100 from chain 200. Pusher member 301 includes an upstanding rear wall 302, extending parallel to the direction of travel of the boxes F on conveyor belt 100 and an upstanding end wall 303, perpendicular to said direction of travel, and facing the boxes approaching on said conveyor. Walls 302 and 303 extend upwardly from a flat horizontal plate 304 positioned at a height above the conveyor belt 100 to just clear the same when the pusher member 301 is moved transversely of the conveyor in a horizontal plane.

Plate 304 of member 301 is mounted by bolts 305 at the upper end 306 of a curved supporting bracket 307 which curves downwardly around the pulley 124, and the conveyor belt 100 trained therearound. The lower end 308 of bracket 307 is formed with a pair of integral sleeves 309 and 310 each slidable on one of a pair of transversely extending rods 311 and 312 mounted on frame 101. The upper end of lever is pivoted at 119 to engage the lower end 300 of bracket 307 and the rotation of cam track causes the lever to return pusher member 301 to its non-operating position when required.

A coil spring 320, having one end 321 attached to pusher member 301 and its other end 322 attached to frame 101 moves the pusher member 301 laterally across conveyor belt 100 when mechanical trip or release mechanisrn 340 is actuated by a box F.

Trip mechanism 340 includes a vertically extending plate 341, pivoted at 342 to hang in the path of the foremost end of a box F approaching on conveyor belt 100. A counterweight 343 is mounted on plate 341 to maintain the lower end 344 thereof in a forwardly projecting position. In this position an edge 345 of plate 341 enters a notch 346 in pusher member 301 and prevents the spring 320 from moving the pusher member across belt 100. However, when a box F has been moved past interceptor element 230 by movable member 231 and permitted to advance on conveyor belt 100 into box transfer zone 300, the foremost end of the box strikes the pivoted plate 341. The pushing of plate 341 rearwardly releases box transfer member 301 so that the pushing surface 356 of its upstanding rear wall 302 contacts the front wall of the box F and sweeps the box laterally across belt conveyor 100 and into box conveyor means B. The upstanding end wall 303 of pusher member 301 also moves across the conveyor to form a barrier to any boxes approaching therealong because of malfunction of the interceptor clement 230 or movable member 231. An upstauding lug 202 advancing with chain 200 contacts the box F as soon as it overlies box conveyor means B and moves the box end or side foremost, continuously through the folding zones 400 and 500 in proper synchronization with tirst folding means D and second folding means E.

An upright post 360 is mounted on bracket 307 of pusher member 301 and is split at its top 361 to receive a rod 362, the rod being adjustable laterally or rotatable at various angles therein by means of set screw 363. R ed 362 extends across the conveyor belt 100 and is then bent at right angles at 364 into a portion 365 forming a pushing surface 366 extending parallel to the direction parses? of travel of the boxes F. The pushing surface 366 is thus above the rear panel 602 of a box' F in the horizontal plane of the cover 605 while the pushing surface 356 of rear wall 302 is adjacent the front panel 601 of the' box and on the lower horizontal plane thereof. I use the term stepped pusher member to thus describe the member 301 since its lower portion at 356 is at the level of the front panel of each box and its upper portion at 366 is at the level of the cover of each box.

The rod 362 and its pushing surface 366 is positioned to push the cover 605 iiatwisel against the rear-wall 201 of the box conveyor means B and to hold the cover in an opstanding position against the vertical rear wall; while the box is advanced in a direction parallel to said upstanding cover into the rst folding zone 400. If a cover is bent backwardly at the time of operation of the box transfer means it will strike the rear Wall 291 and be raised to an upstanding position. lf it is bent forwardly at that time, it will` be contacted by surface 366 and be pushed thereby into an upstanding position. The ldust flaps on the cover are not folded or bent at this time and remain in extension of the cover.

First folding means The first stationary folding means D of the device is located at the rst folding zone 400 and includes ran elongated vertical plate 410, a portion of the elongated rear wall 201 and an elongated, downwardly bent folder bar 440. Plate 410 is bent upwardly from a horizontal plate 411 which extends across the box conveyor meansB at about the height of the wall panels of a box F. Vertical plate 410 is positioned parallel to the rear Wall 201 and spaced therefrom slightly more than the thickness of the box cover which advances between them' thereby supporting the cover from bowing as the folder bar 440 operates. At the same time the plate 411 holds down each box F on the chain 2130 as it passes through the first folding zone 46d. Lateral adjustability of plate 410 is achieved by a bracket 415 which supports plate 411 and is heldin place in a pair of parallel tracks 416 extending transversely of the machine by a bolt 417. Vertical adjustability of plates 411 and 410 is secured by a vertical slot 430 in bracket 415, and a bolt 431 which supports plate 411 at various heights in the slot.

The folder bar 440 is mounted in an adjustable clamp 441 at the `top of a vertical post 442 extending upwardly from frame 101. The bar 440 extends longitudinally of the machine with a portion at 445 positioned to engage the front dust ap 606 of cover 605 of each box F as it enters box conveyor means B. The bar 440-is shaped as at 446'to urge the front dust flap into an infolded position at right angles to the cover as the box F passes thereunder and as the cover is entirely engaged on both sides by wall 201 and plate 410. The free end 447 of bar 440 extends slightly into the second folding zone 500 in order to hold the front dust hap in infolded position until it is engaged in the second stationary folding means of second folding means E.

Second folding means The second folding means E of the invention, located at the second folding zone 500, includes second stationary folding means in the form of an elongated quadrantal plate 502 and continuously moving folding means in the form of an endless chain 501, a pair of pivoted folding arms 503 and 504 and a pivoted closing head 505.

The plate 5li2-is preferably curved to conform generally with the path of the fold line of the front dust flap 606 of each box cover 605 as the cover is closed. It extends the fulllengtli of the second folding zone 500 and confines the infolded front dust hap so that it cannot unfold and so that it remains a chord of the curved plate 502. The front dust flap is delivered, in infolded position from the end of folder bar 440 into the upper entrance 511' of plate 502 andV follows a downward and advancing course as the cover closes andladvancesuntil it` is delivered to' a position',

. 6 and tucked in, behind the front panel 601 of a box F at the lower exit 512 of the plate. Preferably a guide 513' is provided near the upper entrance 5'11 to assure the proper control of the front dust flap at the moment of delivery into plate 502.

Plate 502 is provided with a ange 806 secured to brackets 807 and 808, the brackets each being slidable transversely of the machine in a pair of parallel tracks such as 810 and 811 similar to tracks 214 and 215' for front wall 210 and tracks 416 for plate 410; The plate 502 may thus be moved transversely to accommodate boxes and covers of vari'ous'dir'nensions or other plates of various desired shapes may be substituted for plate 502 where necessary or desirable;

Endless chain 501 is trained around sprockets 144v and 145, the shafts 143 and 146 thereof being journalled in the vertically movable supporting assembly 510. Assembly 510 and chain 501 are mounted in rear of box conveyor means B and are alongside and parallel thereto. The upper stretch 520, of chain 501', travels in the same direction and at the same speed as chain 200, carrying the boxes F, but is at the level of the cover and' dust flap portions of the boxes. As mentioned above, an intermediate portion 220, of rear wall 201, is carried by assembly 510 with its upper edge at about the level of the upper stretch 520 of chain 501 so that it may be lifted and lowered with the same but does not interfere ,with the folding means carried on the chain.

At spaced distances around chain 501 are one or more units made up of a pair of pivoted arms 503l and 504 and a pivoted closing head 505 positioned between them. The travel of chain 501 is synchronized to'place a single unit in rear of the npstanding cover of each successive'box F as it is advanced through the second folding zone and to cause the unit to apply its folding and closing forces as the unit travels along with the cover and box.

The mounting of -the pivotedarms 503 and 504A is similar except that they operate in reverse directions. A plate 540 is fixed to one link 541 of'chain 501 by rivets, or the equivalent, and is provided with a longitudinal slot 542. A carriage 543 is slidably adjustable in slot 542 by means of bolts 544 and includes a front post 546 and a rear postV 547. A bellV crank lever 549 is mounted to pivot horizontally on post 547, one arm 550 carrying a roller cam follower 551 and the other arm 552 being pivotally connected at 553 to the end 554 of a connecting' strap 555. The other end of strap 555 at 556 is pivotally connected at 557 to a member 558V mounted to pivot horizontally on post 546. Member 559 is provided with an arm 503 which is called a pivoted folding arm herein. Arm 503 is provided with a flat surface 561, as shown in the drawings, to contact the side dust aps on one side of a box F. However l' may use a surface withV aprotuberance such as 562 positioned to contact the lower portion of the side dust flap-on a cover, to assure that this portion is well inserted into the box during closing.

A similar plate 570 is xed to another link 571 of chain 501, plate 570 having a slot 573 in which a carriage 574', similar to carriage 543'is slidably mounted. As indicated above, the linkage 572 of carriage 574is similar to, but

the reverse of that described for carriage 543 and includesV a roller cam follower 575, a pivotedfolding arm 504 andA a surface 576 to contact the side dust aps on the other side of the box. A longitudinally extending, horizontal cam track 578 is xed to assembly 510' by bolts 579-in the pathof cam follower 551 for arm 503 and cam follower 575 for arm 504. As the upper stretch 520 of chain 501 advances, the pivoted arms 593 and 504 behind, and along with, the upstanding cover 60S of a box F, cam track 578 causes the pivoted folding arms 503 and 504 to sweep `toward each other in a horizontal plane. It will be obvious that whether the side dust flaps arel on the cover as shown at 607 and( 608 or on the end panels of box F as shown at 609, 610 they will be contacted and infoldedby the arms 5031a'nd'5014:

Between mounting plates 540 and S70, a plate 585 is secured to a link 586 of chain 501, plate 585 having a carriage 587 secured thereto by a bolt 58S. A bell crank lever 589 is pivoted at 590 to carriage 587 and includes an arm 591 carrying a roller cam follower 592 and an other arm 593 to which one end 594 of a connecting strap 595 is pivoted. The other and 596, of strap S95, is pivoted to an arm 597 of a member 598 which in turn is pivoted at 599 to carriage 587. The cover closing head 505, is mounted on member 598 and it will be apparent that when roller cam follower 592 is moved in a vertical plane it will cause closing head 505 to move in a vertical plane. A longitudinally extending, opstanding cam track 801 is fixed to assembly 510 by bolts 802 in the path of roller cam follower 592 to actuate the same.

The cam track 801 is located to move cover closing head S downwardly in a vertical plane simultaneously with the moving of pivoted folding arms S03 and 504 toward each other in an horizontal plane as the folding arms and head are advanced on chain Stil through the second folding zone 500.

The machine will accommodate a great variety of sizes and shapes of boxes in view of the slidable adjustability of the various box contacting parts. For example the front wall 210 and the plate 562 are slidable transversely in tracks 214, 215 and 81d and 11 to accommodate various widths of boxes such as F. The rod 362 is slidable transversely in post 360 and the plate 41@ is slidable transversely in tracks 416 to accommodate various thicknesses of covers such as 605. The plate 411 is slidablc vertically in slot 43) to accommodate boxes of various heights. The pivoted folding arms 503 and 504 are slidable longitudinally by means of slots 542 and 573 to accommodate boxes of various lengths.

In addition to the above adjustable features of the device, the assembly 519 is bodily movable vertically on threaded posts 155 and 156 to accommodate a major change in the size of box used.

In operation, a plurality of filled cartons are carried side foremost in a line along the continuously moving, box receiving, conveyor belt 100 until the side of the first box in line strikes interceptor element 230 and the line of boxes ceases forward movement while the belt continues moving thereunder. When an upstanding lug 202 of chain 200 is ready to receive a box, movable member 231 pushes the first box in line laterally past inter ceptor 230 to travel individually en belt 160 down to the box transfer zone 30) and into contact with pivoted plate 341 of trip mechanism 341. The tripping of plate 341 causes the pusher member 301 to push the box laterally into the path of the lug 202 of chain Ztl() and to push the cover into upstanding position against rear wall 201. Continuously moving chain 200 then carries the box side foremost in a direction parallel to the upstanding cover through first folding zone 400 and through second folding zone 560. ln zone 466 the cover is supported on front and reai surfaces by a portion of rear wall 201 and vertical plate 410 while folder bar 440 infolds the front cover dust flap, these being the first stationary folding means of the invention.

In the second folding zone Siti), the side dust flaps are infolded and the cover downfolded by the pivoted arms 503 and 564 and the pivoted closing head 595 of the continuously moving folding means of the invention while the second stationary folding means, plate 502, holds the front cover dust flap in its infolded position. Each dust iiap is thus tucked into its position behind the panels of the box as the cover is closed to overlie the contents of the box and the closed box is then discharged from the machine A.

I claim:

l. Apparatus for use in closing the upstanding articulated cover and infolding the articulated side dust flaps, of a lled box continuous advancing in a direction parallel to said upstanding cover on box conveyor means,

said apparatus comprising the combination of a folding unit advancing parallel to the path of said box; a pair of side dust flap folding arms each mounted on said unit, behind a side dust flap, to pivot toward the other in an horizontal plane, a cover closing head positioned between said arms and mounted on said unit behind said cover to pivot downwardly therewith in a vertical plane and cam means for pivoting the arms and head of said folding unit while said unit and said box are continuously advancing.

2. A machine for closing filled paper boxes, each box having an upstanding, articulated cover, a front cover dust fiap and a pair of oppositely disposed, articulated, side dust flaps, said machine comprising the combination of continuously moving box conveyor means for continuously advancing said boxes, side foremost, individually and successively through a first folding Zone and a second folding zone in a direction parallel to said upstanding cover; first stationary folding means extending along said fisrt folding zone in the direction of advance of said boxes for supporting the upstanding cover of each box against bowing while simultaneously infolding thc cover dust flap thereof as the box continuously advanaces through said first folding zone; continuously moving folding means, advancing along said second folding zone in the direction of advance of said boxes and alongside each upstanding cover thereof for simultaneously infolding the pair of side dust flaps and downfolding the cover of each box as the box continuously advances through said second folding Zone and second stationary folding means, extending along said second folding zone in the direction of advance of said boxes for holding the cover dust fiap of each box in infolded position during the downfolding of said cover in its passage through said second folding Zone.

3. A machine as specified in claim 2 wherein said first stationary folding means comprises a vertical rear Wall; a vertical plate parallel thereto, uniformly spaced therefrom a distance slightly moi'e than the thickness of said cover and a downwardly curved folder bar positioned to infold the dust flap of each cover while the cover advances between said rear wall and plate.

4. A machine as specified in claim 2 wherein said second stationary folding means comprises a continuous quadrantal piate in the path of the infolded front dust tiap of said cover during the downfolding of said cover in its passage through said second folding zone, said plate being co-extensive with said Zone and extending in thc direction of advance of said bo'xes for a distance greater than the length of a single box.

5. A machine as specified in claim 2 wherein said continuously moving folding means comprises an cndless chain carried unit, a pair of pivoted arms mounted' on said unit to oscillate toward each other in an hori- Zontal plane thereby infolding said articulated side flaps and a pivoted closing head7 mounted on said unit between said arms, to oscillate downwardly in a vertical plane, thereby downfolding said cover.

6. A machine as specified in claim 2 wherein said continuously moving box conveyor means comprises an endless chain, having spaced upstanding lugs spaced apart to each contact the trailing side of an individual box, said chain extending from the beginning of said first folding Zone to the end of the second folding zone and each lug retaining its contact with a box during the passage thereof through both said Zones.

7. A machine specified in claim 2 wherein said first stationary infolding means includes an horizontal plate at the level of the plane of the tops of said boxes for holding said boxes down on said box conveyor means during the operation of said first stationary folding means in said first folding zone.

8. A machine as specified in claim 2 plus a continuously moving box receiving conveyor belt, paralleling and overlapping said continuously moving box conveyor 9 means, in a box transfer zone in advance of said lirst folding zone, and stepped box transfer means in said box transfer zone for pushing each successive box and its upstanding articulated cover an equal distance transversely from said belt into said box conveyor means.

9. A machine a specified in claim 8 plus a stationary box interceptor element at one side of the path of the boxes advancing on said box receiving belt, a movable element positioned adjacent said interceptor element but in advance thereof at the level of a box intercepted thereby and means synchronized with said moving box conveyor means and said box transfer means, for moving said movable element laterally of said belt beyond said interceptor element,

10. A machine as specified in claim 8 wherein said stepped box transfer means comprises a box pusher member having two upstanding walls at the level of said boxes, one said wall being aligned with the front walls of said boxes, and the other said wall being outside, but perpendicular to, the path of said boxes; a pushing surface on said box pusher member at the level of said upstanding covers and aligned with the rear walls of said boxes and mechanism for moving said pusher member transversely across said box transfer -zone in synchronization with said box conveyor means.

11. A machine as speciied in claim 8 plus a trip lever pivotally mounted at the terminal end of said box receiving conveyor belt in said box transfer zone and in the path of boxes carried on said belt and mechanical means, actuated by said trip lever for releasing said box transfer means in synchronization with the rate of advance of boxes on said box conveyor means.

12. Apparatus for closing the upstanding, articulated cover and infolding the articulated cover dust flaps of a filled box continuously advancing in a path parallel to said upstanding cover on box conveyor means, said apparatus comprising the combination of a xed folder bar extending along the path of the front cover dust Hap for infolding said flap; a pair of xed upstanding supports, each extending along an opposite side of the path of said upstanding cover and each coextensive with said folder bar for supporting the cover against bowing during said infolding; a movable folding unit, continuously advancing alongside the path of, and temporarily accompanying, said cover after the release thereof by said supports, said unit having a pair of folding arms mounted to oscillate toward each other in an horizontal plane for infolding the side dust aps of said cover and having a folding head, mounted between said arms, to oscillate in a vertical plane, for downfolding said cover and a iixed quadrantal plate, coextensive with the path of said movable folding unit while accompanying said cover, for retaining the front cover dust flap in infolded position during the downfolding of said cover.

13. The method of automatically and successively closing the upstanding articulated cover, and infolding the articulated front cover and side dust flaps of iilled paper boxes which comprises the steps of continuously advancing said boxes individually and successively, side foremost, in a path parallel to said upstanding cover; simultaneously supporting the opposite tlat surfaces of each successive cover against bowing and applying an infolding force on the cover dust flap thereof during said step of continuously advancing said boxes and then simultaneously holding said cover dust flap in infolded position, applying an infolding force in an horizontal plane on the side dust aps and applying a downfolding force in a vertical plane on the cover during said step of continuously advancing said boxes.

References Cited in the tile of this patent UNITED STATES PATENTS 2,051,339 Little Aug. 18, 1936 2,277,289 Bergstein et al Mar. 24, 1942 2,441,410 Guyer May 11, 1948 

